1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a camera therein.
2. Discussion of the Related Art
Recently, various flat panel display devices have been developed. Examples of the display devices, which have been actively studied, include a liquid crystal display device, a plasma display panel, a field emission display device, and a light emitting display device.
Of the flat panel display devices, the liquid crystal display (LCD) device is a device that displays images using optical anisotropy of a liquid crystal, and is widely used owing to its advantages of thin type, small size, low power consumption, and high picture quality.
FIG. 1 is a plane view illustrating a liquid crystal display device according to the related art, and illustrates that an upper substrate and a lower substrate are bonded to each other by a seal.
According to the liquid crystal display device, the upper substrate and the lower substrate are bonded to each other in a state that a liquid crystal is filled between the upper substrate and the lower substrate. A liquid crystal layer between the upper substrate and the lower substrate is sealed by seals 11e, 11m, 11n and 11p formed outside the liquid crystal panel.
The liquid crystal display device may be divided into a display area where various elements are formed to display images, and a non-display area formed outside the display area. In this case, the seals 11e, 11p, 11m and 11n may be divided into the first seal 11e formed between the first non-display area having a camera therein and the display area, and the second to fifth seals 11f, 11m, 11n, and 11p formed outside the liquid crystal display device at the non-display area of the liquid crystal display device in rectangular shapes, sealing the upper substrate and the lower substrate.
At the lower substrate of the liquid crystal display device, pixels are formed in each area where a gate line crosses a data line. A liquid crystal injected into the pixel is driven by a voltage applied to a common electrode and a pixel electrode formed at the pixel, so as to vary transmittance of light.
The common electrode may be formed in the display area of the upper substrate or the lower substrate. In order to apply a common voltage to the common electrode, a common line 15 connected with the common electrode is formed in the non-display area of the lower substrate or the upper substrate.
With the recent trend of reducing an edge width of the liquid crystal display device, the common line 15 is formed in the upper substrate to overlap with the seals 11e, 11m, 11n and 11p as shown in FIG. 1, wherein the seals are attached onto the common line 15.
When the upper substrate is bonded to the lower substrate by the seals, ultraviolet rays irradiate to the seals from the bottom of the lower substrate, whereby the seals are hardened.
At this time, since the common line 15 overlapping with the seals is formed of metal, it is difficult to harden the seals formed on the common line using the violet rays.
In order to solve this problem, as shown in an enlarged circle of FIG. 1, the common line 15 is formed in a mesh structure of a plurality of lines. In this case, the violet rays irradiated from the bottom of the lower substrate to the seals may harden the seals by transmitting the lines forming the common electrode.
In case of the liquid crystal display device having a camera for video chatting, video conference, etc., as shown in FIG. 1, the first seal 11e formed between the first non-display area 12 and the display area 36 is extended to the first non-display area 12 to surround a through hole 14 formed in the first non-display area to correspond to the camera.
In other words, in the liquid crystal display device according to the related art, light is refracted at an empty space between the lower substrate and the upper substrate where the through hole 14 is formed, whereby a diffraction pattern is generated in the image taken by the camera. In order to prevent such a diffraction pattern from being generated, a method for injecting a liquid crystal into the periphery of the through hole 14 has been used recently. To this end, the first seal 11e formed between the display area 36 and the first non-display area 12 is formed to surround the through hole 14.
Accordingly, no seal is formed between the periphery of the through hole 14 of the first non-display area 12 and the display area. For this reason, the liquid crystal injected into the display area is also injected into the periphery of the through hole 14.
The liquid crystal display device includes a back light unit to irradiate light to the liquid crystal panel 13. The light emitted to the back light unit is emitted to the outside through the liquid crystal panel 13 formed of the lower substrate and the upper substrate.
In this case, as the light irradiated to the non-display area is shielded by the seal, light leakage to the non-display area may be prevented from occurring.
However, since the seal is not formed between the periphery of the through hole 14 and the display area 36 as described above, light leakage may occur in such a manner that the light that has passed through the common line 15 of the mesh structure is displayed in the first non-display area 12. A light leakage area 16 where the light leakage occurs is formed on the common line 15 of the mesh structure formed between the periphery of the through hole 14 and the display area, as shown in FIG. 1.